NSAC's Blog

EPA Releases Water Pollution Data Tool

January 31, 2012

The EPA has just released the Discharge Monitoring Report (DMR) Pollutant Loading Tool, an online database system that allows users to track polluters included in the database. Under the Clean Water Act, facilities with National Pollutant Discharge Elimination System (NPDES) permits report discharge data to the EPA. The EPA has pooled and classified some of this information so that users may track the “who, what, and where” of waterway discharge.

The tool calculates pollutant loadings from NPDES permits and Discharge Monitoring Report (DMR) data from EPA’s Permit Compliance System and Integrated Compliance Information System for the National Pollutant Discharge Elimination System. Currently, the Tool’s database includes information available for the years 2007 through 2010. Pollutant loadings are presented as pounds per year and as toxic-weighted pounds per year to account for variations in toxicity among pollutants. The tool ranks dischargers, industries, and watersheds based on pollutant mass and toxicity, and presents top ten lists to help you determine which discharges are important, which facilities and industries are producing these discharges, and which watersheds are impacted.

The tool also includes wastewater pollutant discharge data from EPA’s Toxics Release Inventory (TRI) for the years 2007 through 2010. Users can search TRI data to find the facilities with the largest pollutant discharges to surface waters or sewage treatment plants. Users can also compare the DMR data search results against TRI data search results and vice versa. The tool clearly labels the source of data when displaying search results but does not mix TRI or DMR data when calculating pollutant discharges

Users of the database can sort data by geographic location, industry, year, and pollutant. Information is displayed in graphs and maps. The DMR tool also ranks pollutant mass and toxicity in “top ten” lists, highlighting the most important pollutants, the facilities or sectors with the worst exceedance records, and the watersheds most affected. The public can then link to enforcement information for those facilities that have violated EPA limits.

The tool is an efficient and accessible means for individuals to track the health their local watersheds. It should be noted, however, that the tool is not particularly useful with respect to Confined Animal Feeding Operations (CAFOs). While CAFOs are point sources, because so many large CAFOs claim not to discharge they are not included in the tool.